1. Field of the Invention
The present invention relates to frozen dessert makers, and more particularly to dessert makers in which a dessert mix is stirred and cooled within a container.
2. Prior Art
Frozen dessert makers, such as those used to make ice cream and other frozen dairy desserts, are well-known and consist of a can for containing the dessert mix to be frozen, a stirring means for agitating the mix within the can, and a larger container containing an icy brine bath within which the can is placed. The dessert mix is agitated within the can it is cooled by the icy brine bath. As the ice in the bath melts, the agitated mix can be cooled to a temperature below that of the freezing point of the ice due to the latent heat of fusion of the icy brine bath.
In order to increase the rate of heat transfer from the dessert mix within the can to the icy brine solution, it is commonly known to rotate the can within the brine solution. This serves to agitate the brine solution and thereby eliminate any temperature gradient from the surface of the can to the solution which would reduce heat flow from the can.
Similarly, the contents of the can must be agitated so that ice crystals which form on the inner surface of the can may slice off and mix with the dessert mix and thereby maintain a uniform temperature of the contents. Since heat is generated by the mixing of the contents of the can, it is desirable to increase the rate of heat flow from the dessert mix within the can to the brine solution in order to decrease the time needed to make the frozen dessert mix.
The frozen dessert makers presently used possess distinct disadvantages. It is necessary to make an icy brine solution each time a frozen dessert is to be made. After the frozen dessert is made, the icy brine solution must be emptied from the dessert maker, resulting in a waste of water and salt and possibly creating problems in locating a proper place to dispose of the brine solution. In addition, frozen dessert makers commonly used agitate this coolant, somewhat due to the rotation of the can, but the coolant is not circulated sufficiently, resulting in an increased time needed to freeze the dessert mix due to temperature gradients within the brine bath.